The present invention relates to an actuator device. A device of this type is known from DE 10 2009 014 304, and furthermore, US 2004/206922 A1 also shows one such device.
It is known from the prior art (and also from the underlying general actuator technology, which is assumed to be known), to use magnetically effective shape memory alloy materials (MSM materials=magnetic shape memory, here equivalent in meaning to ‘magnetischer—FGL=Formgedächtnislegierung’) for actuator technology. Thus, typically for this purpose, an MSM (FGL) crystal body (as a representative for a multiplicity of possible MSM-based materials), typically produced on the basis of an NiMnGa alloy, is loaded with a magnetic field generated by means of an energised coil. As a reaction to such a magnetic field loading, the MSM crystal body carries out an expansion movement as an expansion body or expansion means, the travel of which expansion movement generally runs in a direction perpendicular to the magnetomotive-force direction with the electromagnetically generated field. This expansion movement can then, at a driven end, drive an adjustment partner interacting suitably with this end, for example a generic adjusting body.
Thus, magnetically effective shape memory alloy materials of this type and actuators (actuator devices) realised using the same in the described principal manner offer an option to replace or to complement current magnet-based actuator principles—such as electromagnetic actuators for example. In the case of the magnetic shape memory alloy material used, in addition to constructive mechanical simplicity in terms of realisation (there is no armature that moves as a whole, it is merely an expansion of the expansion means that takes place), wherein a pivot lever here effects the force transmission between the individual actuators.
Also advantageous in the case of MSM-based push-push systems of this type is the fact that the adjusting body (suitably driven in an opposed manner longitudinally or rotationally) by both individual actuators is currentlessly stable at practically any adjustment position between end positions of the respective adjustment movements; in other words, by means of suitable control, an MSM push-push system of this type—which is assumed to form the generic type—is able to hold the adjusting body in currentlessly stable positions along the movement path—moved bidirectionally—and thus to carry out adjustment tasks in particular, which do not require permanent energising or position regulation, as long as external forces do not exceed a predetermined level.
Whilst a technology of this type is less affected by the previously explained problem of a reduced maximum expansion travel of the MSM expansion means, nonetheless, the realisation of a push-push system of this type by means of two interacting MSM actuators entails considerable hardware and component outlay, as for each individual adjustment element, not only a respective MSM expansion body, but also a respectively assigned coil unit, which generates the required magnetic field, including additional flux-conducting means and also mechanical coupling elements are required.
Reference is made to US 2010/242673 A1 for the additional prior art.